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Biomedical subjects

H M van Praag

Publications and source records attributed to H M van Praag.

At least 73 records · Page 4Linked to original sources
PubMed1991

Pituitary hormone responses to meta-chlorophenylpiperazine in panic disorder and healthy control subjects.

The present study reports adrenocorticotropic hormone (ACTH) and prolactin responses after oral administration of 0.25 mg/kg of the serotonin agonist, meta-chlorophenylpiperazine (MCPP), in patients with panic disorder (PD) and in healthy subjects. MCPP blood levels were similar for the two groups, but almost twice as high in males as in females. Female patients had augmented ACTH and prolactin release as compared to healthy females, while ACTH and prolactin release in male patients was similar to that of male controls. These results suggest that female PD patients have hypersensitive serotonin receptors. Moreover, they indicate that pharmacokinetic gender differences may affect challenge studies, and that different doses may be required to study neuroendocrine responses in males and females.

Adrenocorticotropic Hormone↗
PubMed1991

Correlates of risk of suicide in violent and nonviolent psychiatric patients.

OBJECTIVE: This study was designed to identify variables that correlate with the risk of suicide in two patient groups that differ mainly in their level of expressed aggression. METHOD: Twenty-eight psychiatric patients with a history of violent behavior who were in a forensic psychiatric facility were tested and compared to 28 psychiatric inpatients without a history of violence who were admitted to a large municipal hospital. Measures used included a battery of self-report questionnaires, with acceptable reliability and validity, that provided indices of risk of suicide, risk of violence, impulsivity, anger, anxiety, and various mood states. RESULTS: The two groups, matched on demographic variables and overall risk of suicide, differed significantly on the measured risk of violence. The two groups showed similar patterns of correlations between risk of suicide and such variables as risk of violence, anger, fear, state and trait anxiety, lack of impulse control, suspiciousness, and rebelliousness. They differed in the correlation between suicide risk and depression. In the nonviolent patients there was a high correlation between risk of suicide and sadness; in the violent patients there was no correlation between these variables. CONCLUSIONS: The low correlation between sadness and risk of suicide in the violent patients, and the low prevalence of affective disorder diagnoses in these patients compared to other patients, suggests that suicidal risk should be managed differently in highly violent patients than in others.

Adult↗
PubMed1990

Neurological signs and the positive-negative dimension in schizophrenia.

Schizophrenic patients have been observed to manifest a variety of abnormal neurological signs, but the nature of their association with differing clinical presentations is less well established. To address this issue, we administered a newly compiled neurological inventory to 28 well-characterized chronic schizophrenic inpatients and separately assessed them on the Positive and Negative Syndrome Scale and on control variables that included measures of global pathology, chronicity of illness, neuropsychological and intellectual integrity, and extrapyramidal dysfunction. We found, first, that our neurological battery provided statistically independent measures of apraxia, fine motor function, and prefrontal, parietal, and nonlocalizing signs. A significant association emerged between negative symptomatology and neurological signs of prefrontal impairment (p less than 0.01), which could not be accounted for by any of the control variables. Positive symptoms were associated with an absence of parietal and nonlocalizing signs; however, these correlations were mediated by higher neuroleptic doses in these patients. There was no association between any neurological sign and age, extrapyramidal symptoms, general neuropsychological integrity, education, IQ, or severity or chronicity of illness. We concluded that the negative syndrome in schizophrenia represents a distinct dimension of psychopathology that is related specifically to prefrontal deficit.

Adult↗
PubMed1990

Effects of m-chlorophenylpiperazine in normal subjects: a dose-response study.

m-Chlorophenylpiperazine (MCPP), a direct 5HT receptor agonist, was administered orally to 20 normal subjects in two doses (0.25 and 0.5 mg/kg) in a placebo-controlled design. Behavioral responses; ACTH, cortisol, prolactin and MCPP blood level; temperature and pulse rate were measured over a 210-min period after administration of tablets. Non-linear dose-response relationships between MCPP and ACTH, cortisol and prolactin response were found. On the higher dose, a significant increase in the number of physical symptoms was also noted and three subjects (15%) had a panic attack, while one subject (5%) had a panic attack on the lower dose. No effects on other behavioral variables, pulse rate and temperature were found using either dose. These findings attest to the usefulness of MCPP as a challenge agent to assess 5HT receptor hypersensitivity when given at a low oral dose (i.e. around 0.25 mg/kg), and to assess 5HT receptor hyposensitivity when given at higher oral doses (i.e. around 0.5 mg/kg).

Adrenocorticotropic Hormone↗
PubMed1990

Two-tier diagnosing in psychiatry.

This article addresses the question: what is the most productive way to systematize abnormal behavior in order to study its biological roots? Though nosology still occupies the premier position in biological psychiatry, it is, in and by itself, a treacherous beacon. Syndromal organization of psychopathology is likewise seriously flawed. A functional organization of psychopathology is considered the most appropriate framework for biological research and a plea is made for a two-tier diagnostic system of psychiatric disorders. Tier one comprises the nosological diagnosis, and tier two a detailed depiction of the component psychological dysfunctions. Such a two-tier diagnostic system would bring psychopathology onto a true scientific footing.

Brain↗
PubMed1990

Effects of serotonin antagonists on m-chlorophenylpiperazine-mediated responses in normal subjects.

The serotonin (5HT) agonist, m-chlorophenylpiperazine (MCPP), has been used as a challenge agent to assess central 5HT receptor sensitivity in normal subjects and patients with panic disorder, obsessive-compulsive disorder, and major depression. Adrenocorticotropin, cortisol, and prolactin responses to MCPP were among the variables measured. MCPP's usefulness as a probe of 5HT receptors, however, hinges on its 5HT selectivity. To address MCPP's selectivity for 5HT, this study tested whether two different 5HT antagonists, methysergide (4 mg p.o.) and metergoline (4 mg p.o.), could block the hormonal and behavioral effects of MCPP (0.5 mg/kg p.o.) in 10 normal male subjects in comparison to placebo. Both 5HT antagonists abolished the prolactin release to MCPP. Metergoline, the antagonist with the more potent 5HT binding affinity, significantly blocked MCPP's effect on cortisol release as compared to placebo, and methysergide showed a nonsignificant trend to that effect. MCPP alone did not have a significant effect on behavioral variables, perhaps explaining why neither 5HT antagonist affected these measures. The findings from this study suggest that both MCPP-induced prolactin release and cortisol release are indeed 5HT-mediated effects.

Administration, Oral↗
PubMed1990

Interrelationships among anxiety, aggression, impulsivity, and mood: a serotonergically linked cluster?

Serotonin abnormalities appear to be related to a variety of psychopathological dimensions such as anxiety, depressed mood, impulsivity, and aggression dysregulation. We hypothesized that the psychopathological dimensions related to serotonin would be significantly intercorrelated since they seem to have a common biological basis. Sixty psychiatric inpatients were examined on a series of psychometric tests measuring suicidality, violence potential, impulsivity, depressive mood, and anxiety. The scores on all of these measures tended to be significantly correlated with one another. These findings support the additional hypothesis that biological markers may be more closely related to basic psychological dimensions than to nosological categories.

Adult↗
PubMed1990

Psychological test characteristics of depressed and panic patients.

This study compared the psychological test performance of patients with major depression (MD) (n = 23), patients with panic disorder (PD) (n = 20), and normal subjects (n = 24). Results indicated that scores of normal subjects were significantly less pathological than those of both patient groups on almost all psychological test scales, but that the test performance of the two patient groups did not differ. The only difference between the two patient groups was on the level of self-reported and observer-rated depression. Both patient groups exhibited significant personality pathology, and the rate of personality disorders diagnosed by the Millon Clinical Multiaxial Inventory (MCMI) (base rate greater than 84) was 73% for PD patients and 86% for MD patients. The problems of assessing personality during episodes of MD and PD and the possible overdiagnosis of personality disorders by the MCMI are discussed.

Adult↗
PubMed1990

Significance of cocaine history in schizophrenia.

Fifty-one schizophrenic inpatients were divided into two groups, those with and without history of cocaine use, and compared on historical, demographic, cognitive, and psychopathological measures. Patients with a cocaine history were found to be significantly more depressed, less socialized, and more impaired in conceptual encoding and verbal memory, while less disordered in attention. The two groups did not differ in severity of illness or positive and negative syndromes. There were also no differences in control variables such as age, gender, education, intelligence, premorbid adjustment, neuroleptic dose, onset and chronicity of illness, continuity of hospitalization, paranoid subtype, and psychiatric illness in the family. Cocaine history was associated with multiple illicit drug use, but for other substances there was no increased liability for depression or cognitive deficits. The results suggest that the clinical presentation in schizophrenia is significantly associated with prior cocaine experience.

Adult↗
PubMed1990

Monoamines and abnormal behaviour. A multi-aminergic perspective.

Classical nosology has been the cornerstone of biological psychiatric research; finding biological markers and eventually causes of disease entities has been the major goal. Another approach, designated as 'functional', is advanced here, attempting to correlate biological variables with psychological dysfunctions, the latter being considered to be the basic units of classification in psychopathology. Signs of diminished DA, 5-HT and NA metabolism, as have been found in psychiatric disorders, are not disorder-specific, but rather are related to psychopathological dimensions (hypoactivity/inertia, increased aggression/anxiety, and anhedonia) independent of the nosological framework in which these dysfunctions occur. Implications of the functional approach for psychiatry include a shift from nosological to functional application of psychotropic drugs. Functional psychopharmacology will be dysfunction-orientated and therefore geared towards utilising drug combinations. This prospect is hailed as progress, both practically and scientifically.

Arousal↗
PubMed1990

The DSM-IV (depression) classification: to be or not to be?

In 1958, when I started my residency training in psychiatry, diagnostic confusion reigned in the realm of depressive disorders. Diagnostic concepts were not operationalized, nomenclature was not standardized, and no taxonomy was generally accepted. What is the situation today, some 30 years later? Today we work under the patronage of the DSM-III classification of depression, a system in which diagnostic concepts are operationalized, nomenclature is standardized, and this nomenclature is officially accepted in the United States and de facto accepted in numerous countries all over the world. Did that system provide order where chaos reigned? The answer has to be in the negative.

Depressive Disorder↗